[codex] Move instance settings under company settings (#7680)

## Thinking Path

> - Paperclip is the open source app people use to manage AI agents for
work
> - Operators manage both company-scoped configuration and
instance-level runtime/admin settings from the board UI
> - Instance settings previously lived as their own top-level sidebar
area, separate from the company settings context operators already use
> - That split made settings navigation feel heavier and made instance
configuration less discoverable from the settings tab
> - This pull request moves instance settings under company settings
while preserving the existing instance settings routes and plugin/admin
surfaces
> - The benefit is a smaller primary sidebar and a more coherent
settings hierarchy for operators

## Linked Issues or Issue Description

- Refs #338
- Internal: PAP-10491, PAP-10538

## What Changed

- Moved instance settings navigation under the company settings area.
- Added route helpers and sidebar entries for nested instance settings
paths.
- Updated plugin/admin settings routes to use the company settings
instance scope.
- Preserved legacy instance-settings bookmarks through compatibility
redirects that keep the active company prefix.
- Updated focused UI and plugin tests for the new navigation shape.
- Stabilized the process-loss retry test that was failing the serialized
server shard in CI.
- Rebased the branch onto current `paperclipai/paperclip` `master` and
pushed the current head.

## Verification

- `pnpm exec vitest run
ui/src/components/CompanySettingsSidebar.test.tsx
ui/src/components/access/CompanySettingsNav.test.tsx
ui/src/lib/instance-settings.test.ts
ui/src/components/InstanceSidebar.test.tsx
ui/src/components/Layout.test.tsx
ui/src/components/SidebarAccountMenu.test.tsx
ui/src/pages/PluginPage.test.tsx ui/src/plugins/bridge.test.ts
packages/shared/src/validators/plugin.test.ts`
- `pnpm exec vitest run ui/src/lib/instance-settings.test.ts
ui/src/components/CompanySettingsSidebar.test.tsx
ui/src/components/access/CompanySettingsNav.test.tsx
ui/src/components/Layout.test.tsx ui/src/plugins/bridge.test.ts`
- `pnpm exec vitest run
server/src/__tests__/heartbeat-process-recovery.test.ts -t "queues
exactly one retry when the recorded local pid is dead"`
- `pnpm test:run:serialized -- --shard-index 0 --shard-count 4`
- GitHub PR checks are green on head
`fe7b0955169dcae55cbe10889c1876a70ab0b80c`, including `verify`, `General
tests (server)`, all serialized server shards, build, e2e, policy,
security checks, and Greptile.
- Confirmed the PR diff does not include `pnpm-lock.yaml` or
`.github/workflows` changes.

## Risks

- Medium UI/navigation risk: instance settings links are intentionally
moving under company settings, so stale external bookmarks to legacy
paths rely on the compatibility routing in this branch.
- Low test-only risk from the CI stabilization commit: it makes the
recovery assertion select the actual retry run by `retryOfRunId` instead
of whichever non-original run appears first.
- No database migrations.
- No dependency lockfile or workflow changes.

> For core feature work, check [`ROADMAP.md`](ROADMAP.md) first and
discuss it in `#dev` before opening the PR. Feature PRs that overlap
with planned core work may need to be redirected — check the roadmap
first. See `CONTRIBUTING.md`.

## Model Used

- OpenAI Codex coding agent based on GPT-5, with shell/tool execution in
a local repository worktree. Exact context window was not exposed by the
runtime.

## Checklist

- [x] I have included a thinking path that traces from project context
to this change
- [x] I have specified the model used (with version and capability
details)
- [x] I have checked ROADMAP.md and confirmed this PR does not duplicate
planned core work
- [x] I have searched GitHub for duplicate or related PRs and linked
them above
- [x] I have either (a) linked existing issues with `Fixes: #` / `Closes
#` / `Refs #` OR (b) described the issue in-PR following the relevant
issue template
- [x] I have run tests locally and they pass
- [x] I have added or updated tests where applicable
- [ ] If this change affects the UI, I have included before/after
screenshots
- [x] I have updated relevant documentation to reflect my changes
- [x] I have considered and documented any risks above
- [x] All Paperclip CI gates are green
- [x] Greptile is 5/5 with no open P2s, recommendations, or follow-ups
- [x] I will address all Greptile and reviewer comments before
requesting merge

---------

Co-authored-by: Paperclip <noreply@paperclip.ing>

ui/src/pages/PluginManager.tsx

@@ -100,7 +100,8 @@ export function PluginManager() {
   useEffect(() => {
     setBreadcrumbs([
       { label: selectedCompany?.name ?? "Company", href: "/dashboard" },
-      { label: "Settings", href: "/instance/settings/heartbeats" },
+      { label: "Settings", href: "/company/settings" },
+      { label: "Instance settings", href: "/company/settings/instance/general" },
       { label: "Plugins" },
     ]);
   }, [selectedCompany?.name, setBreadcrumbs]);
@@ -307,7 +308,7 @@ export function PluginManager() {
                             </Button>
                           )}
                           <Button variant="outline" size="sm" asChild>
-                            <Link to={`/instance/settings/plugins/${installedPlugin.id}`}>
+                            <Link to={`/company/settings/instance/plugins/${installedPlugin.id}`}>
                               {installedPlugin.status === "ready" ? "Open Settings" : "Review"}
                             </Link>
                           </Button>
@@ -359,7 +360,7 @@ export function PluginManager() {
                   <div className="min-w-0 flex-1">
                     <div className="flex flex-wrap items-center gap-2">
                       <Link
-                        to={`/instance/settings/plugins/${plugin.id}`}
+                        to={`/company/settings/instance/plugins/${plugin.id}`}
                         className="font-medium hover:underline truncate block"
                         title={plugin.manifestJson.displayName ?? plugin.packageName}
                       >
@@ -463,7 +464,7 @@ export function PluginManager() {
                         </Button>
                       </div>
                       <Button variant="outline" size="sm" className="mt-2 h-8" asChild>
-                        <Link to={`/instance/settings/plugins/${plugin.id}`}>
+                        <Link to={`/company/settings/instance/plugins/${plugin.id}`}>
                           <Settings className="h-4 w-4" />
                           Configure
                         </Link>